Not sure if I can sum up for you:
ISO: 100/200/400/800..... The higher the numbers, the grainy it will be.
Aperture: F1.8/F2.0/F2.4/F.2.8..... The amount of light that enters through your lens
Shutter Speed: 1, 1/10, 1/50, 1/100..... The length of time your shutter is open when taking a...